The short answer
Red to the dead battery positive, red to the donor positive, black to the donor negative, black to an unpainted metal ground on the dead car — never the dead battery's negative terminal. Start the donor, wait two minutes, start the dead car.
Order matters. The final clamp goes on bare metal away from the battery because that is where the spark happens.
Step by step
- Park the cars close but not touching. Both ignitions off, both in park with handbrakes on.
- Attach red clamp to the dead battery positive (+).
- Attach the other red clamp to the donor battery positive (+).
- Attach black clamp to the donor battery negative (−).
- Attach the final black clamp to an unpainted metal bolt or bracket on the dead car's engine block.
- Start the donor car, run for two minutes.
- Start the dead car. If it does not turn over in 5 seconds, stop and wait a minute.
- Remove the clamps in exact reverse order, then drive for at least 20 minutes.
What it costs
| Item | Typical cost |
|---|---|
| Jump leads | $20–$50 |
| Lithium jump pack (No second car needed) | $60–$130 |
| New battery | $100–$250 fitted |
| Roadside call-out | $80–$180 |
Common questions
Why not the dead negative terminal?
Batteries vent hydrogen. The last connection sparks — keep it away from the battery.
It died again the next morning?
The battery will not hold charge, or the alternator is not charging. Get both tested.
Hybrids and EVs?
Never use one as a donor. Check the manual — many have specific jump points.